Value transfer contributes to ambiguous-cue discrimination learning

Pigeons learned two concurrent simultaneous discriminations in which the S2 for one served as the S1 for the other. When all correct choices were reinforced, accuracy on the former (positive vs. ambiguous-cue or PA) discrimination was lower than on the latter (negative vs. ambiguous-cue or NA) discrimination. When correct choices on the PA discrimination were intermittently reinforced, however, pigeons chose the S2 more often than the S1 on those trials. By contrast, intermittently reinforcing correct choices on the NA discrimination did not affect NA-trial accuracy but yielded higher PA-trial accuracy relative to continuous reinforcement. Together with a separate preference assessment, these results indicate that value transfer, in which some of the positive value accrued by an S1 transfers to its companion S2, contributes to ambiguous-cue performances.